Buttonhole sizing devices, in themselves, are not new, however, previously known buttonhole sizing devices have usually been used to mark the size of proposed buttonholes on a garment before the garment was moved to the sewing position of a sewing machine.
It is also known in the art to provide a buttonholing mechanism associated as a part of a pattern cam arrangement for a needle-jogging and work-feeding mechanism of the sewing machine for automatically varying the pattern cam operation so as to produce the buttonhole stitch formation, wherein a buttonhole sizing device coacts with the above buttonholing mechanism to obtain a desired size of buttonhole. The buttonholing mechanism disclosed in U.S. Pat. No. 3,596,618 by Goldbach to which this invention is related, has a wheel which rests upon the material being sewn so that the wheel turns as the material is being fed to provide sensing pulses at preset intervals which control electromechanisms for the proper operation of a buttonholing assembly of a household zigzag sewing machine. However, the size of the buttonhole must be known or measured in order to preset the sensing wheel for desired size of buttonhole.